A laminated glass is a safety glass because few glass fragments are scattered even if it is broken by impact from the outside. Therefore, laminated glasses have been used widely for windowpanes of motor vehicles such as automobiles, aircrafts, buildings, and the like. Examples of laminated glasses include glasses obtained by inserting, between at least one pair of glasses, an interlayer film for a laminated glass which contains polyvinyl acetal plasticized by a plasticizer, and then by uniting them, and then by laminating them.
When laminated glasses are used as windowpanes of motor vehicles such as automobiles, aircrafts, and buildings, they are used under a condition exposed to irradiation of ultraviolet rays. A conventional interlayer film for a laminated glass contains ultraviolet absorbers so as to block ultraviolet rays. Most ultraviolet absorbers contained in interlayer films for laminated glasses block only ultraviolet rays having wavelength of 380 nm or shorter. Therefore, an interlayer film for a laminated glass containing the ultraviolet absorbers cannot sufficiently block ultraviolet rays having wavelength of 380 to 400 nm.
As an example of an interlayer film for a laminated glass to overcome the problem mentioned above, Patent Document 1 discloses an interlayer film for a laminated glass containing a synthetic resin, an ultraviolet absorber, and a yellow dye which absorbs light having wavelength of 380 to 450 nm. It is said that the interlayer film for a laminated glass disclosed in Patent Document 1 can block light having wavelength of 450 nm or shorter while maintaining lighting-transmitting properties. However, Patent Document 1 does not consider any method for homogeneously dispersing the yellow dye in the interlayer film for a laminated glass, and thus it is not possible to obtain an interlayer film for a laminated glass having high visible light transmittance. And also, the interlayer film for a laminated glass disclosed in Patent Document 1 has a problem that practically it cannot sufficiently block ultraviolet rays having wavelength of 380 to 400 nm.
And also, Patent Document 2 discloses an interlayer film containing a synthetic resin material with an organic light absorber added thereto. As examples of the organic light absorbers, ultraviolet absorbers, blue light absorbers, infrared absorbers, and red light absorbers are described. However, the organic light absorbers described in Patent Document 2 cannot sufficiently block ultraviolet rays having wavelength of 380 to 400 nm.    Patent Document 1: Japanese Kokai Publication 2000-300149 (JP-A-2000-300149)    Patent Document 2: Japanese Kokai Publication 2007-290923 (JP-A-2007-290923)